Seatbelt assemblies and systems are in widespread use in motor vehicles. Present systems have certain common elements including seatbelt webbing which extends across the upper and lower torso of the occupant, and a retractor for allowing protraction and retraction of the webbing so that the belt may adapt to different sizes of occupants and be conveniently out of the way when not being used. Seatbelt assemblies further typically include a buckle which releasably attaches to a latch plate.
Seatbelt assemblies must be securely affixed to motor vehicle structural elements in order to provide the necessary restraint effect in vehicle impact conditions and further to meet government regulations. Further, seatbelt assemblies must securely retain an occupant within its seat, while also allowing the occupant easy ingress and egress from the seat under a variety of conditions and situations.
Typical seatbelt assemblies include a buckle that is securely mounted to a vehicle structure, such as a seat frame or the floor of the occupant compartment. The buckle typically includes a slot that is sized to receive and retain a latch plate.
The latch plate is typically attached to the seatbelt webbing. The seatbelt webbing is typically fixed to the vehicle structure at one end, and the opposite end is typically fixed to a retractor in the form of a spool that is configured to protract and retract the webbing in response to various loads. The latch plate is typically attached by passing the seatbelt webbing through an elongate opening or slot, such that the latch plate can slide along the webbing and be adjusted relative to the size of the occupant. The latch plate is typically attached to webbing such that the latch plate remains on the webbing, whether the seatbelt is in the buckled or unbuckled configuration.
One type of latch plate includes a simple elongate opening, such that the webbing will freely slide through the opening without substantial restriction from adjustment. Pulling on either end of the webbing by the occupant relative to the latch plate will allow the webbing to be adjusted. However, in the event of a rapid deceleration of the vehicle, the webbing is likewise free to travel through the opening in response to movement of the occupant. Some present systems include latch plates that will pinch the webbing at the latch plate when significant load is applied.
Another type of latch plate includes a housing, through which the webbing can pass. The housing includes a translatable lock bar that can slide along the housing. By sliding the lock bar, the webbing can be locked in place, thereby preventing the webbing from moving relative to the latch plate. However, this approach makes it difficult to adjust the webbing for the occupant.
Another type of seatbelt system can include two retractors, where one retractor is attached at the top of a shoulder belt portion of the seatbelt, and the other is attached at the end of a lap belt portion. The shoulder belt portion and lap belt portion are each stitched to a latch plate that is received by a traditional buckle. In this system, the belt portions do not move relative to the latch plate. However, this system is expensive because it requires two retractors.
A seatbelt clamping device in accordance with this invention provides the advantage of avoiding the need for a latch plate, saving cost and weight. The invention also provides for greater ease of use, making it easier to find and attach the belt by grabbing the seatbelt webbing without having to locate and adjust the latch plate.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings.